Allow butter and eggs to stand at room temperature 30 minutes. Meanwhile, grease and lightly flour sixteen 3-1/4-inch (large) muffin cups; set aside. In medium bowl stir together flour, cocoa powder, baking soda, baking powder, and salt; set aside.
Preheat oven to 350 degrees F. In large mixing bowl beat butter with mixer on medium to high for 30 seconds. Gradually add sugar, 1/4 cup at a time, beating on medium until well combined. Scrape bowl; beat 2 minutes more. Add eggs one at a time, beating after each addition. Beat in vanilla. Alternately add flour mixture and milk, beating on low after each addition just until combined. Beat on medium 20 seconds. Spoon batter into cups, filling each about two-thirds full.
Bake cakes for 15 to 18 minutes, until tops spring back when lightly touched. Cool in cups on racks 5 minutes. Remove; cool completely on wire racks. Frost cooled cakes with White Chocolate Frosting.
White Chocolate Curls
Line a 5-3/4x3x2-inch loaf pan with plastic wrap; set aside. In microwave-safe bowl, heat white chocolate for 1 minutes. Stir. Heat 1 to 2 minutes more, stirring every 30 seconds, until melted. Pour into pan. Freeze for 15 minutes. To shave curls, let candy stand at room temperature. Line a baking sheet with parchment or waxed paper. Holding candy with paper towels over paper, use a peeler to shave curls along wide side of candy. If candy becomes soft, refrigerate a few minutes. Chill curls. To decorate cakes, use a pick to lift curls and place against frosted cakes. Sprinkle with edible glitter.
White Chocolate Frosting
In small saucepan melt white baking chocolate over low heat, stirring frequently. Set aside to cool. In large mixing bowl beat butter and vanilla with mixer on medium for 30 seconds. Gradually beat in 3 cups powdered sugar. Add milk. Gradually beat in remaining powdered sugar. Beat in melted white chocolate until combined. If necessary, for spreading consistency, beat in 1 to 2 tablespoons additional milk.